JP7387324B2 - Image reading device, sheet feeding device, and image forming device - Google Patents

Description

The present invention relates to an image reading device that reads image information from a sheet, a sheet feeding device that feeds the sheet, and an image forming device that forms an image on a recording material.

An image reading device installed in a copying machine or an image reading device used alone is equipped with a document tray on which original sheets are stacked, and the sheets stacked on the document tray are fed and read one by one. There are things that perform actions. The document tray may be configured to be able to rotate above the tray position for feeding sheets in order to facilitate the removal of scanned sheets discharged below the document tray.

By the way, if the user releases the document tray after lifting it, the document tray may fall with force and collide with the frame of the image reading device, causing a loud noise or damaging the components. There is sex. Patent Document 1 describes that a rotary damper is used to slow down the fall of the document tray.

Japanese Patent Application Publication No. 2004-359409

However, in the configuration described in the above document, in order to generate a sufficient amount of torque in the rotary damper, it is necessary to configure the gear train so that the rotational speed of the rotary damper increases relative to the angular velocity of the document tray's descent. was there. This has been an impediment to miniaturization and cost reduction of image reading devices.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an image reading device, a sheet feeding device, and an image forming device that have a simple configuration and can suppress the descending speed of a rotating member.

One aspect of the present invention includes a stacking member on which sheets are stacked, a feeding device that feeds the sheets stacked on the stacking member, and a feeding device that is provided below the stacking member and that is fed by the feeding device. a discharge section from which sheets are discharged; a device main body that rotatably supports the stacking member between a lower position and an upper position above the lower position; and a damper unit attached to the device main body. a damper unit that has a cylindrical cylinder part and a piston part inserted into the cylinder part, and expands and contracts in an expansion and contraction direction when the cylinder part and the piston part slide; and a damper unit provided on the loading member. When the loading member descends from the upper position to the lower position, the damper unit is pressed in the expansion/contraction direction to contract, thereby increasing the descending speed of the loading member. a contact portion disposed so as to be restrained; The sheet feeding device has a guiding portion that faces the cylinder portion and slidably guides the cylinder portion in the expansion/contraction direction, and the contact portion contacts the cylinder portion.

According to the present invention, the descending speed of the rotating member can be suppressed with a simple configuration.

1 is a schematic diagram of an image forming apparatus according to a first embodiment. 1 is a sectional view of a scanner according to a first embodiment. FIGS. 3A and 3B are diagrams (a, b, c) showing the support structure of the document tray according to the first embodiment; FIGS. FIG. 3 is a schematic diagram of a scanner according to a second embodiment. FIG. 3 is a schematic diagram of a scanner according to a third embodiment.

Hereinafter, exemplary embodiments for carrying out the present invention will be described with reference to the drawings.

<Example 1>
Example 1 will be explained. FIG. 1 is a schematic diagram showing an image forming apparatus 100 that is an electrophotographic laser beam printer. The image forming apparatus 100 includes a scanner 3 as an image reading apparatus that reads image information from a document D, an image forming apparatus main body (hereinafter referred to as a printer main body) 10 that forms an image on a recording material, and the scanner 3 and the printer main body 10. A control unit 50 is provided. The original or recording material may be paper such as plain paper or thick paper, plastic film, cloth, surface-treated sheet materials such as coated paper, sheet materials with special shapes such as envelopes or index paper, etc., depending on size and size. A variety of sheets made of different materials can be used.

The printer main body 10 includes an image forming section 20 that forms an image on a sheet S which is a recording material, a main body feeding section 30 and a manual feeding section 40 that feed the sheet S to the image forming section 20, A discharge tray 49 from which the sheet S is discharged is provided.

The main body feeding section 30 includes a plurality of cassettes 30a that can be inserted into and pulled out from the printer main body 10, and a feeding unit 30b that feeds the sheets S stored in each cassette 30a one by one. The sheet S fed by the feeding unit 30b is conveyed toward the registration roller 11 via a conveyance path provided inside the printer main body 10. The manual feed unit 40 includes a manual feed tray 40a that is rotatably supported by the printer main body 10 and can be opened and closed from the side of the printer main body 10, and one sheet S placed on the manual feed tray 40a in an open state. and a feeding unit 40b that feeds each portion at a time. The sheet S fed by the feeding unit 40b is also conveyed toward the registration roller 11 via a conveyance path provided inside the printer main body 10. After correcting the skew of the sheet S, the registration roller 11 sends the sheet S toward the transfer device 24 in accordance with the progress of the process of forming a toner image in the image forming section 20 .

The image forming unit 20 performs an electrophotographic process to form an image on the sheet S based on image information read from the document D by the scanner 3 or image information input from an external information processing device. That is, in the image forming section 20, the surface of the photosensitive drum 22, which is a photosensitive member, is uniformly charged by the charger 26. The laser scanner 27 irradiates the photosensitive drum 22 with laser light for scanning exposure, thereby writing an electrostatic latent image based on image information on the drum surface. This electrostatic latent image is developed as a toner image using developer supplied from the developing device 23. The toner image carried on the photosensitive drum 22 is transferred from the photosensitive drum 22 to the sheet S by an electrostatic bias formed by a transfer device 24. At this time, the conveyance of the sheet S by the registration roller 11 is controlled so that the timing at which the toner image carried on the photosensitive drum 22 reaches the transfer device 24 and the timing at which the sheet S is fed into the transfer device 24 are synchronized. be done.

A fixing device 25 is arranged downstream of the transfer device 24 in the conveyance direction of the sheet S. The fixing device 25 includes a pair of rotating bodies that rotate while sandwiching the sheet S, and a heat source such as a halogen lamp that heats the toner image on the sheet via the pair of rotating bodies, and heats the toner image while conveying the sheet S. Heat and pressurize. As a result, the toner is melted and then fixed, whereby an image fixed on the sheet S is obtained.

The sheet S that has passed through the fixing device 25 is discharged from the printer main body 10 by a pair of discharge rollers 48 and stacked on a discharge tray 49 . Note that when forming images on both sides of the sheet S, after the image formation on the first side of the sheet S is performed, the sheet S is conveyed again toward the registration roller 11 via the reversing conveyance path 12. Ru. Thereafter, when an image is formed on the second side of the sheet S by passing through the transfer device 24 and the fixing device 25, the sheet S is discharged onto a discharge tray 49 by a pair of discharge rollers 48.

The image forming section 20, which is a direct transfer type electrophotographic unit described above, is an example of an image forming means that forms an image on a recording material. When the present technology is applied to an image forming apparatus, the image forming means may be an intermediate transfer type electrophotographic unit that transfers a toner image formed on a photoreceptor onto a sheet via an intermediate transfer body. Furthermore, not only the electrophotographic unit but also an inkjet printing unit or an offset printing mechanism may be used as the image forming means.

(Schematic configuration of scanner)
FIG. 2 is a sectional view of the scanner 3 according to this embodiment. The scanner 3 includes a flatbed portion 2 that is a flatbed type reading unit, and an ADF 1 that serves as a sheet feeding device that feeds sheets that serve as original documents. However, ADF is an abbreviation for automatic document feeder. In the image forming apparatus 100 shown in FIG. 1, the flatbed section 2 is fixed to the upper part of the printer main body 10, and the ADF 1 is rotatably supported by the flatbed section 2 and can be opened and closed on the top surface of the flatbed section 2. It is composed of

In this embodiment, image sensors 31 and 32, which serve as reading means for reading image information from a document, are arranged on both the flatbed section 2 and the ADF 1. The image sensor 31 provided on the flatbed section 2 reads image information from the reading surface of the document placed on the document table glass 28 and the first surface of the document conveyed by the ADF 1. The image sensor 31 provided in the ADF 1 reads image information from the second side of the document being transported by the ADF 1 . The image sensors 31 and 32 each include a light guide that irradiates the original with light from a light source, image sensors 31a and 32a that photoelectrically convert an optical image of the original, and images that reflect light from the original on the image sensor. and an optical system. In the illustrated example, so-called CCD image sensors 31 and 32 are used, which use a charge-coupled device as an image sensor and a reduction optical system as an optical system. A contact image sensor (CIS) may also be used.

The flatbed section 2 includes a document table glass 28 on which a stationary document is placed, a platen glass 29, and an image sensor 31. The document platen glass 28, which is a transparent member, is arranged to face the pressure plate 18 provided on the lower surface of the ADF 1 when the ADF 1 is closed. The image sensor 31 is mounted on a carriage driven by a carriage motor M3, and is movable in the sub-scanning direction (horizontal direction in the figure) in the space below the document table glass 28 and platen glass 29.

The ADF 1 includes a document tray 6 as a stacking member on which documents are placed, an ADF main body 1A that feeds and conveys documents one by one from the document tray 6, and a stack of documents ejected from the ADF main body 1A. A discharge tray 8 is provided.

The document tray 6, which is a rotating member of this embodiment, includes a tray main body 60 rotatably supported by the frame of the ADF main body 1A, a loading table 61 supported by the tray main body 60 as a supporting member, and a loading platform 61 supported by the tray main body 60 as a supporting member. It has a lifter 63 that raises and lowers the table 61. The tray body 60 is rotatably supported by the ADF body 1A, which constitutes a part of the apparatus body of the image reading device, and is placed on the upstream side in the document feeding direction Fd (left side in the figure) with respect to the ADF body 1A. It stands out. A loading table 61 serving as a loading section on which a document is placed is vertically rotatable with respect to the tray body 60 around a lift fulcrum 6a provided at an upstream end in the feeding direction Fd. The lifter 63 is disposed below the loading platform 61, and is rotated together with the lifter driving shaft 63a by rotation of the lifter driving shaft 63a by the driving force of the lift motor M1, thereby raising and lowering the loading platform 61. . Further, the document tray 6 is provided with a pair of side edge regulating plates 9 that come into contact with both ends of the document in the width direction (direction perpendicular to the feeding direction Fd) to regulate the document position.

The ADF main body 1A has a transport path that forms a transport path from the document tray 6 to the output tray 8 via the reading positions of the image sensors 31 and 32, and a transport path that feeds the original from the document tray 6 and transports the original through the transport path. It has a plurality of roller members for. When viewed from the width direction of the document (the main scanning direction of the image sensors 31 and 32), the document tray 6 is positioned directly above the output tray 8, and the conveyance path of the ADF main body 1A is folded back in a U-shape. There is. That is, the feeding direction Fd (left side in the figure) in which the document is fed from the document tray 6 and the discharge direction (right side in the figure) in which the document is discharged from the ADF main body 1A to the output tray 8 are horizontal directions. The components of are in opposite directions.

The plurality of roller members provided in the ADF main body 1A include a pickup roller 41, a feeding roller 42, a separation roller 43, conveyance rollers 71, 72, 73, 74, and a discharge roller 75. The pickup roller 41 serving as the feeding means in this embodiment is disposed above the loading table 61 of the document tray 6, and is supported by an arm member 46 that is swingable about a drive shaft 45 that supports the feeding roller 42. has been done. By controlling the posture of the arm member 46 by a cam mechanism or the like using power from a motor (not shown), the vertical movement of the pickup roller 41 with respect to the loading platform 61 is controlled. The pickup roller 41 is driven by the feeding motor M2 and rotates while in contact with the upper surface of the uppermost original loaded on the stacking table 61, thereby moving the uppermost original in the feeding direction Fd. send out.

The feeding roller 42 rotates around a drive shaft 45 and further conveys the document received from the pickup roller 41 in the feeding direction Fd. The separation roller 43 comes into contact with the feeding roller 42 to form a separation nip, and is connected via a torque limiter to a shaft member fixed to the frame of the ADF main body 1A. The separation roller 43 is an example of a separation member for transporting sheets to be fed in a separated state one by one, and is a retard roller to which a driving force in a direction opposite to the feeding direction Fd is input, or a feeding roller. A pad-shaped friction member that abuts 42 may be used as a separating member.

The conveyance rollers 71 to 74 are conveyance means in this embodiment that conveys the original that has passed through the separation nip along a curved conveyance path. The ejection roller 75 is an ejection means in this embodiment that ejects the document whose image information has been read to the outside of the ADF main body 1A.

The flow of the operation of reading image information while conveying a document using the ADF 1 (skimming operation) will be described below.

FIG. 2 shows a state of waiting for the user to place a document. In this state, the document tray 6 is at a predetermined lower position, and the loading table 61 is not lifted up. When the sensor installed on the document tray 6 detects that a document has been placed on the loading table 61, the control section provided in the scanner 3 starts driving the lift motor M1 to lift up the loading table 61. I do. When the sensor detects that the uppermost document on the loading platform 61 has reached a predetermined height, the control section stops driving the lift motor M1. When receiving an instruction to start a reading operation from the user, the control section starts rotating the pickup roller 41 while keeping the pickup roller 41 in contact with the uppermost document. As a result, the original is fed out from the original tray 6 toward the separation nip in the feeding direction Fd.

The document fed out by the pickup roller 41 is further conveyed toward the conveyance roller 71 by the feed roller 42 . At this time, when a plurality of documents enter the separation nip, the separation roller 43 applies a frictional force in the opposite direction to the feeding direction Fd to the documents other than the topmost document in contact with the feeding roller 42. to prevent double feeding of originals.

The transport rollers 71 to 75 transport the original while passing it along a curved transport path. In the process, the original is scanned at a first reading position where the image sensor 31 of the flatbed section 2 scans the original through the platen glass 29, and at a second reading position where the image sensor 32 of the ADF main body 1A scans the original. pass. Then, the first and second sides of the document are optically scanned by the image sensors 31 and 32, and image information converted into electronic signals by the image sensors 31a and 32a is acquired. The document that has passed the reading positions of the image sensors 31 and 32 is discharged onto the discharge tray 8 by the discharge roller 75. At this time, the position of the original in the ejection direction is regulated by a swingable original holding guide 69 hanging downward from the original tray 6, and the originals ejected one by one are stacked on the ejection tray 8. Thereafter, the user removes the document from the output tray 8, thereby completing the series of operations.

(Original tray support structure)
Here, the support structure of the document tray 6, which is a rotating member of this embodiment, will be explained using FIGS. 3(a to 3c). As described above, the document whose image information has been read by the flow-reading operation is discharged to the discharge tray 8 below the document tray 6. At this time, depending on the user's physique and the amount of documents loaded on the ejection tray 8, it may be preferable to lift the document tray 6 in order to secure space for accessing the documents and improve visibility.

Therefore, as shown in FIG. 3(a), the document tray 6 is supported by the ADF main body 1A in a rotatable state about the support shaft 60a. Hereinafter, the position of the document tray 6 when placing the document on the document tray 6 will be referred to as an initial position (home position). That is, the document tray 6 can be rotated from the initial position, which is the lower position in this example, to the lifted position (the upper position in this example) as shown in FIG. 3(b). .

As shown in FIG. 3A, a cylinder damper 7 is attached to the ADF main body 1A as a damper unit that cushions the document tray 6 from falling. The cylinder damper 7 includes an outer tube 7b containing a spring, and a piston rod 7a inserted through the outer tube 7b. The piston rod 7a as a piston part is constituted by a piston valve inserted into an outer tube 7b as a cylinder part, and a resin cap protruding outward from the outer tube 7b.

The cylinder damper 7 expands and contracts with the axial direction of the outer tube 7b being the expansion and contraction direction by sliding movement of the piston rod 7a and the outer tube 7b. At this time, a force that resists the relative movement of the piston rod 7a and the outer tube 7b is generated due to viscous resistance of the fluid (oil, air, etc.) sealed in the outer tube 7b. Further, the spring included in the outer tube 7b generates a biasing force between the piston rod 7a and the outer tube 7b that tends to restore the cylinder damper 7 to the expanded state.

The tray body 60 of the document tray 6 is provided with an abutting portion 60b as an abutting portion for pressing the cylinder damper 7 to produce a damping effect. The abutting portion 60b is provided at a position away from the support shaft 60a (that is, away from the rotational axis of the document tray 6) when viewed from the axial direction of the support shaft 60a of the document tray 6, and prevents the rotation of the document tray 6. Along with the movement, it moves in an arcuate trajectory around the support shaft portion 60a.

The cylinder damper 7 is disposed in a position perpendicular to the axial direction of the support shaft portion 60a of the document tray 6, and in a position where the abutment portion 60b abuts as the document tray 6 rotates. Particularly, in the illustrated example, the cylinder damper 7 is arranged in such a position that the document feeding direction Fd substantially coincides with the contraction direction when viewed in the vertical direction.

Further, in this embodiment, the piston rod 7a is fixed to the ADF main body 1A, and the outer tube 7b is supported by the ADF main body 1A in a slidable state in the expansion and contraction direction. That is, as shown in FIG. 3(c), the ADF main body 1A includes a holding portion 5a that holds the piston rod 7a in a state where movement in the expansion and contraction direction is restricted, and an outer tube 7b that is slidable relative to the piston rod 7a. It has a guide part 5b that guides the user. The holding portion 5a restricts the movement of the piston rod 7a to one side and the other side in the contraction direction by engaging with the resin cap of the piston rod 7a. The guide portion 5b is constituted by a member facing the cylindrical outer peripheral surface of the outer tube 7b, and forms a space extending in the contraction direction so as to accommodate the outer tube 7b.

With such a configuration, when the cylinder damper 7 is pressed by the abutment part 60b that draws an arcuate locus with the support shaft part 60a as the rotation center, a component force in a direction intersecting the expansion/contraction direction is applied to the cylinder damper 7. can reduce the effect of In other words, in a modified example in which the outer tube 7b is fixed to the ADF main body 1A and the piston rod 7a is moved by being pressed by the abutting portion 60b, the piston rod 7a is tilted in a direction intersecting the expansion/contraction direction, and a load is applied to the cylinder damper 7. It may take. According to the configuration of this embodiment, since the generation of such a load is suppressed, it is possible to use a small cylinder damper 7 with relatively low strength. However, this does not exclude implementation in the form of the above-mentioned modification.

Hereinafter, among the expansion and contraction directions of the cylinder damper 7, the direction in which the outer tube 7b moves so that the engagement with the piston rod 7a becomes shallow (the right side in FIG. 3) will be referred to as the "extension direction", and the opposite direction (in FIG. ) is defined as the "shrinkage direction". That is, the abutment part 60b of the document tray 6 abuts the end of the outer tube 7b in the extension direction (which is referred to as the pressed part), and compresses the cylinder damper 7 by pressing the outer tube 7b in the contraction direction. The structure is as follows.

X1 and X2 in FIGS. 3A and 3B represent the end positions of the stroke of the cylinder damper 7. That is, the contracted position X1 represents the position of the outer tube 7b in the state shown in FIG. 3A, in which the cylinder damper 7 is most contracted with respect to the direction of expansion and contraction of the cylinder damper 7. The contracted position X1 is the position of the outer tube 7b when the document tray 6 is at the initial position. In addition, the extended position X2 represents the position of the outer tube 7b in the state shown in FIG. 3(b) in which the cylinder damper 7 is most extended with respect to the direction of extension and contraction of the cylinder damper 7. However, all positions represent the position of the outer tube 7b with respect to the pressed portion.

The abutting portion 60b of the document tray 6 presses the outer tube 7b in the range from the extended position X2 to the contracted position X1. Here, the reference position X0, which is directly below the support shaft portion 60a in the expansion/contraction direction, is located within the range from the expansion position X2 to the contraction position X1 (FIGS. 3(a, b)). Since the abutting portion 60b draws an arcuate locus around the support shaft portion 60a, the moving direction of the abutting portion 60b at the moment it passes this reference position X0 coincides with the direction of expansion and contraction. Such an arrangement also contributes to reducing the force acting on the cylinder damper 7 in a direction intersecting the expansion/contraction direction.

Further, the guide portion 5b provided in the ADF main body 1A is configured to guide the outer tube 7b over the entire stroke of the cylinder damper 7. In other words, the guide portion 5b is connected to the outer periphery of the outer tube 7b until the outer tube 7b moves from one end position (X2) to the other end position (X1) in the movable range of the outer tube 7b. It is formed so that it remains facing the surface.

Hereinafter, the action of the cylinder damper 7 as the document tray 6 rotates will be explained.

When the user grasps the document tray 6 at the initial position shown in FIG. 3(a) and lifts it to the position shown in FIG. 3(b), the abutting portion 60b of the document tray 6 moves in the direction in which the cylinder damper 7 extends. do. At this time, the resistance force of the cylinder damper 7 does not act on the document tray 6, and the outer tube 7b moves from the contracted position X1 toward the extended position X2 due to the action of the spring.

The document tray 6 can be rotated further upward than the angle shown in FIG. 3(b) (a predetermined position that is the limit of the range in which the abutting portion 60b and the cylinder damper 7 can come into contact). In this case, the abutting portion 60b of the document tray 6 moves in the direction in which the cylinder damper 7 extends from the extended position X2 and separates from the outer tube 7b.

Thereafter, when the user releases the document tray 6, the document tray 6 begins to descend (fall) toward the initial position due to its own weight. When the document tray 6 is lowered to a predetermined position on the way, the abutting portion 60b of the document tray 6 comes into contact with the outer tube 7b at the extended position X2. When the document tray 6 further descends from this state, the abutment portion 60b presses the outer tube 7b in the direction of contraction, so that the cylinder damper 7 contracts.

The resistance force generated when the cylinder damper 7 is contracted acts as a force that causes the outer tube 7b to push back the abutment portion 60b in the direction of extension. In other words, the reaction force received from the outer tube 7b when the abutment portion 60b pushes the cylinder damper 7 generates a torque that tends to push the document tray 6 upwards around the support shaft portion 60a. In this way, the document tray 6 descends while receiving the resistance force generated by the cylinder damper 7, and the descending speed of the document tray 6 is suppressed.

As described above, in this embodiment, the cylinder damper 7 is arranged on the ADF main body 1A, and the abutment part 60b is arranged on the document tray 6, so that the abutment part 60b hits the cylinder damper 7 when the document tray 6 is lowered. It is configured to be pushed in. Thereby, a mechanism for suppressing the descending speed of the document tray 6, which is a rotating member, can be realized with a simple configuration without using a rotary damper. That is, a mechanism such as a gear train, which is necessary to generate a sufficient braking force in the rotary damper, becomes unnecessary.

Further, in this embodiment, of the outer tube 7b and the piston rod 7a that constitute the cylinder damper 7, the outer tube 7b is pressed by the abutting portion 60b and is slid. With this configuration, compared to a configuration in which the piston rod 7a is slid by the abutting portion 60b, it is possible to easily secure a distance that allows the piston rod 7a to be guided opposite the outer circumferential surface of the sliding member. In other words, when the piston rod 7a slides, in order to prevent the piston rod 7a from tilting due to the force in the direction intersecting the direction of expansion and contraction, the cylindrical guide structure for guiding the resin cap must be made longer in the direction of expansion and contraction. need to be formed. On the other hand, since the outer tube 7b itself has a cylindrical shape extending in the expansion and contraction direction, stable operation of the cylinder damper 7 can be realized with a more compact guide structure (the guide portion 5b of this embodiment). can.

(Modified example)
In the above embodiment, the stacking table 61 of the document tray 6 is configured to be movable up and down with respect to the tray body 60, but the document placement surface may be formed integrally with the tray body 60. In this case, as the pickup roller 41 moves up and down, the pickup roller 41 comes into contact with and separates from the document placed on the document tray 6.

Further, in the above embodiment, the cylinder damper 7 is attached to the ADF main body 1A, but the cylinder damper 7 can also be attached to the document tray 6. In that case, the ADF main body 1A is provided with an abutting portion so that the abutting portion abuts against the cylinder damper 7 and operates the cylinder damper 7 when the document tray 6 is lowered.

<Example 2>
In the first embodiment, a mechanism for cushioning the fall of the document tray of the scanner has been described, but in the second embodiment, a mechanism for cushioning the fall of the pressure plate unit is provided in a flatbed type image reading apparatus.

FIG. 4 is a side view showing a scanner 3A as an image reading device according to this embodiment. The scanner 3A includes a flat bed section 2 and a pressure plate unit 1B that is supported on the flat bed section 2 via a hinge 33 so as to be openable and closable. The flatbed section 2 is the main body of the apparatus in this embodiment, and the pressure plate unit 1B is the rotating member in this embodiment.

As in the first embodiment, the flatbed section 2 includes an image sensor movable in the sub-scanning direction and a document table glass 28, which is a transparent member on which a document is placed. A white pressure plate 18 is attached to the lower surface of the pressure plate unit 1B, and when the pressure plate unit 1B is closed, the pressure plate 18 presses the original onto the document table glass 28. In this state, the image sensor optically scans the document while moving below the document table glass 28, and the image sensor's image sensor converts the reflected light from the document into an electronic signal, thereby reading the image data of the document. It will be done.

In this embodiment, a cylinder damper 21 as a damper unit is attached to the flat bed section 2. The cylinder damper 21 includes an outer tube 21b containing a spring, and a piston rod 21a inserted through the outer tube 21b. The pressure plate unit 1B is provided with an abutment portion 60c as an abutment portion for pressing the cylinder damper 21 to produce a damper action. The abutting portion 60c is provided at a position away from the rotational axis of the hinge 33 when viewed from the axial direction of the hinge 33, and moves in an arcuate trajectory around the hinge 33 as the pressure plate unit 1B opens and closes. do.

The cylinder damper 21 is arranged perpendicularly to the rotational axis of the hinge 33 at a position where the abutting portion 60c comes into contact with the rotation of the pressure plate unit 1B. Particularly, in the illustrated example, the cylinder damper 7 is arranged in such a posture that the direction of expansion and contraction substantially coincides with the vertical direction.

Further, the piston rod 21a is fixed to the frame of the flat bed section 2, and the outer tube 21b is supported by the frame of the flat bed section 2 in a slidable state in an expansion/contraction direction. That is, the flatbed portion 2 includes a holding portion that holds the piston rod 21a in a state where movement in the expansion and contraction direction is restricted, and a guide portion that slidably guides the outer tube 21b relative to the piston rod 21a.

As shown in the figure, when the pressure plate unit 1B is open, the upper end of the outer tube 21b, which is the contact surface with the abutting portion 60c, protrudes above the flat bed portion 2 due to the biasing force of the spring. As the pressure plate unit 1B is rotated downward, the abutting portion 60c comes into contact with the upper end of the outer tube 21b of the cylinder damper 21 at a predetermined angle (predetermined position) and begins to press the outer tube 21b downward. Then, the downward speed of the pressure plate unit 1B is suppressed by the resistance force generated as the cylinder damper 21 contracts. The braking action of the cylinder damper 21 continues until the pressure plate unit 1B reaches the lower limit position of the rotation range (position for reading an image).

In this way, also with the configuration of this embodiment, a mechanism for suppressing the descending speed of the pressure plate unit 1B, which is a rotating member, can be realized with a simple configuration.

Note that the pressure plate unit 1B may be biased upward by a spring member attached to the hinge 33, thereby reducing the burden of the opening operation and maintaining the opened state. In this case, the pressure plate unit 1B will not fall freely but will descend while receiving the biasing force of the spring member, but depending on the force of the user's closing operation, the pressure plate unit 1B may collide with the flatbed section 2 with force. There is sex. Therefore, as in the first embodiment, by braking the descent of the pressure plate unit 1B using the cylinder damper 21, the effect of reducing damage and noise caused by collisions between members can be obtained.

(Modified example)
In the example shown in FIG. 4, the cylinder damper 21 is attached to the flatbed portion 2, but the cylinder damper 21 may be attached to the pressure plate unit 1B. In that case, the cylinder damper 21 is attached so that the outer tube 21b protrudes from the lower side of the pressure plate unit 1B, and the abutment part that comes into contact with the lower end of the outer tube 21b when the pressure plate unit 1B is closed is connected to the flat bed part 21. Provided at the top of the

<Example 3>
As a third embodiment, a configuration in which a mechanism for cushioning the fall of the ADF 1 is provided will be described. FIG. 5 is a side view showing a scanner 3B as an image reading device according to this embodiment. The scanner 3B includes a flatbed section 2 and an ADF 1 that is supported on the flatbed section 2 via a hinge 34 so as to be openable and closable. The flatbed section 2 is the main body of the apparatus in this embodiment, and the ADF 1 is the rotating member in this embodiment. The internal configurations of the flatbed section 2 and ADF 1 are similar to those described in the first embodiment.

Similar to the second embodiment, the cylinder damper 21 is attached to the flatbed section 2. The cylinder damper 21 includes an outer tube 21b containing a spring, and a piston rod 21a inserted through the outer tube 21b. The ADF 1 is provided with an abutment portion 60c as an abutment portion for pressing the cylinder damper 21 to produce a damper action. The abutting portion 60c is provided at a position away from the rotational axis of the hinge 33 when viewed from the axial direction of the hinge 33, and moves in an arcuate trajectory around the hinge 33 as the pressure plate unit 1B opens and closes. do.

The cylinder damper 21 is arranged perpendicularly to the rotational axis of the hinge 33 at a position where the abutting portion 60c comes into contact with the rotation of the ADF 1. Particularly, in the illustrated example, the cylinder damper 7 is arranged in such a posture that the direction of expansion and contraction substantially coincides with the vertical direction.

Further, the piston rod 21a is fixed to the frame of the flat bed section 2, and the outer tube 21b is supported by the frame of the flat bed section 2 in a slidable state in an expansion/contraction direction. That is, the flatbed portion 2 includes a holding portion that holds the piston rod 21a in a state where movement in the expansion and contraction direction is restricted, and a guide portion that slidably guides the outer tube 21b relative to the piston rod 21a.

As shown in the figure, when the ADF 1 is open, the upper end of the outer tube 21b, which is the contact surface with the abutting portion 60c, protrudes above the flat bed portion 2 due to the biasing force of the spring. As the ADF 1 is rotated downward, the abutting portion 60c comes into contact with the upper end of the outer tube 21b of the cylinder damper 21 at a predetermined angle (predetermined position) and begins to press the outer tube 21b downward. Then, the downward speed of the ADF 1 is suppressed by the resistance force generated as the cylinder damper 21 contracts. The braking action of the cylinder damper 21 continues until the ADF 1 reaches the lower limit position of the rotation range.

In this manner, also with the configuration of this embodiment, it is possible to realize a mechanism for suppressing the descending speed of the ADF 1, which is a rotating member, with a simple configuration. Note that, as explained in the modification of the second embodiment, the cylinder damper 21 is attached to the ADF 1 which is a rotating member, and the cylinder damper 21 is brought into contact with the cylinder damper 21 by the abutting portion provided on the flat bed portion 2. may be activated.

(Other embodiments)
In Embodiments 1 to 3 above, a configuration was described in which a cylinder-shaped damper unit dampens the downward movement of a rotating member provided in a scanner, which is an example of an image reading device, but the present technology is not limited to this. . A cylinder-shaped damper unit can dampen the downward movement of a rotating member provided in the image forming apparatus (for example, the manual feed tray 40a that is openable and closable on the side surface of the printer main body 10 in FIG. 1). In the case of the manual feed tray 40a, the cylinder damper 21 is attached to the frame of the printer main body 10, and an abutment part is provided as part of the manual feed tray 40a, which contacts and contracts the cylinder damper 21 as the manual feed tray 40a is opened. Bye.

1... Sheet feeding device, rotating member (ADF) / 1A... Device main body (ADF main body) / 1B... Rotating member (pressing plate unit) / 2... Device main body (flat bed part) / 3, 3A... Image reading device (Scanner) /5a...Holding section/5b...Guiding section/6...Rotating member, loading member (document tray)/7, 21...Damper unit (cylinder damper)/7a, 21a...Piston rod/7b, 21b...Cylinder part (outer tube) /20...image forming means (image forming part)/31, 32...reading means (image sensor)/41...feeding means (pickup roller)/60b, 60c...abutting part (abutting part) /100...Image forming device

Claims (8)

a loading member on which sheets are loaded;
feeding means for feeding the sheets stacked on the stacking member;
a discharge section provided below the stacking member, from which sheets fed by the feeding means are discharged;
a device main body that rotatably supports the loading member between a lower position and an upper position above the lower position;
The damper unit is attached to the device main body, and includes a cylindrical cylinder part and a piston part inserted into the cylinder part, and expands and contracts in the expansion and contraction direction by sliding the cylinder part and the piston part. a damper unit that
A contact portion provided on the loading member that presses the damper unit in the expansion/contraction direction to contract when the loading member descends from the upper position to the lower position. a contact portion arranged so that the descending speed of the loading member is suppressed ;
The apparatus main body includes a holding part that holds the piston part in a state in which movement in the expansion/contraction direction is restricted, and a holding part that faces an outer circumferential surface of the cylinder part and slidably guides the cylinder part in the expansion/contraction direction. It has a guide section;
The abutting portion abuts the cylinder portion,
A sheet feeding device characterized by: The guide portion is in a state opposite to the outer circumferential surface of the cylinder portion until the cylinder portion moves from one end position to the other end position in the movable range of the cylinder portion in the expansion/contraction direction. is formed to maintain
The sheet feeding device according to claim 1 , characterized in that: a position within a range in which the loading member can rotate while the contacting portion is in contact with the damper unit, where the moving direction of the contacting portion as the loading member rotates matches the expansion/contraction direction; includes,
The sheet feeding device according to claim 1 or 2, characterized in that: The contact portion is provided at a position away from the rotation axis of the loading member,
The damper unit is arranged in a posture in which the direction of expansion and contraction perpendicularly intersects the direction of the rotational axis of the loading member.
The sheet feeding device according to any one of claims 1 to 3 , characterized in that: When the loading member is at the upper position, the contact portion is separated from the damper unit, and when the loading member is lowered from the upper position to the lower position, the lower position and the upper position are separated. The contact portion is configured to continue pressing the damper unit in a range from a predetermined position between
The sheet feeding device according to any one of claims 1 to 4 . The loading member projects upstream of the apparatus main body in the sheet feeding direction by the feeding means,
The damper unit is disposed below the rotational axis of the loading member, and is attached to the apparatus main body in a posture in which the expansion/contraction direction and the feeding direction match when viewed in the vertical direction,
The contact portion presses the damper unit downstream in the feeding direction when the loading member descends toward the lower position.
The sheet feeding device according to any one of claims 1 to 5 . A sheet feeding device according to any one of claims 1 to 6 ,
reading means for reading an image of the sheet fed by the feeding means;
An image reading device characterized by: An image reading device according to claim 7 ;
an image forming means for forming an image on a recording material;
An image forming apparatus characterized by:

Images